Presuming you are talking about acne...
Environmental, dietary, and hormonal factors are the main causes of "flare ups" in acne prone skin.
Smog and pollution deposit irritants into the skin, and while you are often able to wash these irritants away, sometimes, they become inflamed and cause pimples.
Greasy, fat heavy foods often contribute to poor skin. A simple dietary change is making sure you eat a lot of fibre, and get your Omega 3 fatty acids.
Hormones can also affect the production of oil in your skin- this is why Birth Control often assists in controlling acne.
Oily and fried food can cause flare up with the acne rosacea.
Cause a fire, no. However, if conditions are right, it can cause a fire to flare up.
Doe smoking cause lupus flare ups
according to my medical doctor, stress can cause hemroids to flare up. stress does not cause hemroids.
Most unlikely to be the cause of flare up
It is not unheard of that a condition like hives can coincide with a flare up in arthritic condition's,
taking this can actually cause a flare up before your levels are under control
In the context of the allergic wheal and flare reaction, the flare is the redness one sees on the skin after an allergen has been injected. The wheal is the indurated (hard) bump.
The flare is easier because you don't need to keep yourself up in the air.
Rheumatoid arthritis flare up, eczema, goiter, and open skin lesions.
yeah, a gas flare
An attack or exacerbation or flare